It is generally accepted in the eavestroughing trade that metal fittings are used with metal eavestroughing and plastic fittings are used with plastic eavestroughing. Several approaches have been taken in the past to simplify the installation of metal eavestroughing on homes, such as in the use of cast brackets which are secured to the eaves to retain the metal trough in position. However, casting of brackets is relatively expensive. The standard spike and furrel is, therefore, commonly used in attaching metal eavestrough to an eave. In the line of plastic eavestroughing several advances have been made in providing fittings to join plastic trough and secure it to an eave. Such plastic troughing and fittings may be of the type disclosed in U.S. Pat. No. 3,355,895. There are several drawbacks, however, in using plastic eavestroughing, in that it readily cracks in the colder climates such as when a ladder is placed against the troughing. The thermal expansion of plastic troughing is substantially greater than metal and is in the range of at least ten times greater; therefore, special fittings have to be devised to accommodate this substantial variation in the length of the trough during seasonal changes in climate. The complex structures that are, therefore, devised may be of the type shown in the above-referred to U.S. patent to accommodate this thermal expansion in plastic fittings. The further problem encountered with respect to plastic troughing is that it is usually extruded, thereby requiring year-round production of the trough in order to accumulate sufficient inventory to meet the demands of spring, summer and fall construction trades. With the best of extruders used, it is appreciated in the art that only about 750 feet of trough may be extruded in an hour. Therefore, to avoid year-round production, more extruders may be purchased; however, this proves to be extremely costly, since one extruder may be in the range of $150,000 to $200,000 capital investment. As a result, the manufacture of plastic troughing requires a very high capital investment which makes it very difficult to maintain profitable margins in the industry with the wide fluctuation in the cost of plastic resin.
A further drawback that has been encountered in the use of plastic eavestroughing systems is that the trough cannot be formed of plastic which can maintain a dark colour over extended periods of time. Most plastic troughing is, therefore, of the lighter pastel colours which limits the market to which the troughing may be directed. It is now desired by the consumer that darker eavestroughing be provided to match various darker roof colours. With the darker colours of plastic eavestroughing, the problem encountered is that the ultra-violet radiation tends to bleach the trough over period of time, so that its life is limited.
I have discovered that the use of a roll-formed sheet metal eavestrough with plastic injection molded fittings, therefore, provides substantial advantages. In using the metal eavestrough with plastic fittings, the thermal expansion/contraction of the metal is substantially less than in plastic, as already mentioned. The use of metal eavestroughing is an all-weather type of installation, in that during the winter time, no concern need be given to cracking induced by blows, such as placing a ladder against the house or due to wide variations in expansion and contraction of the metal. The steel may be zinz coated, primed and covered with a topcoat of paint to give any desired colour where the life expectancy of such coats is roughly twenty years. The steel is easier to install in that it has a smoother sidewall portion and due to its particular construction is more flexible to permit snapping of the troughing into the fittings. The paint coat on the steel readily resists ultra-violet degredation to thereby meet the demands of the marketplace with respect to darker coloured material. As mentioned, one of the problems with former metal systems is that it was difficult to form the fittings out of metal; however, in adapting the use of plastic fittings, they are readily injection molded. In roll-forming the eavestroughing, it is appreciated that such units require substantially less capital investment and roll-forming speeds of approximately 9,000 feet per hour can be achieved which is roughly 12 times the rate of production with respect to extruding plastic eavestroughing. As a result, the fluctuating demands of the marketplace with respect to eavestroughing can be met on a more short-term basis resulting in substantially less carry of inventory throughout the year.
It is, therefore, an object of the invention to provide an eavestroughing system which is far superior to known metal eavestroughing systems and known plastic eavestroughing systems.
It is a feature of the invention to accomplish such object in the combined use of a roll-formed sheet metal eavestrough with plastic injection molded fittings or supports therefor.
The above-identified advantages flow from this feature of the invention.